The principal aim of this study is to provide preliminary information in chimpanzees on the safety, immunogenicity and efficacy of a new, chemically synthesized hepatitis B vaccine. These data are a necessary prerequisite to future studies in humans. To accomplish this goal a l6 amino acid HBsAg synthetic peptide will be cyclized and formulated into alum-absorbed micelles or covalently linked to tetanus toxoid and absorbed onto alum. These preparations will be inoculated into five chimpanzees. After a primary series of inoculations, the animals will be challenged with a known quantity of infectious hepatitis B virus to determine whether immunity has been established. A sixth animal will serve as a control for the challenge inoculum. Animals will be followed for evidence of clinical/biochemical disease, humoral and cell-mediated immunity.